Relay control system



July 31,1934. w. H. GILLE l RELAY CONTROL YSTEM Filed April 30. 1932 J J j /0 f g I z:

[NIP/V701? MAL/5 l7. 6/: Y

QTMTMJ M Patented July 31, 1934 UNITED STATES I 1,968,385 PATENT OFFICE Application April 30, 1932, 'Serial No. 608,480

6 Claims.

This invention relates to improvements in relay controlling devices and has, as its main object, to so control a relay of the bucking coil type that unfailing proper operation is assured, and chattering prevented.

In relays of the bucking coil type, the armature is generally biased to open and is moved to and held in closed position as a result of energization of a first or operating coil, and is released to move to open position, as a result-of energization of a second or bucking coil which neutralizes the magnetic effect of the first coil. It is the usual practice to have the armature control one or more contacts, one of which may control an external load or loads or perform any other desired work".

In prior art devices of the general class to which this invention relates, the relay is ordinarily controlled automatically, for example by a double contact thermostaticswitch. Whenthis switch closes one of its contacts, energization of the operating coil occurs, the armature closes, and a relay holding contact is also closed for maintaining energization of the operating coil, following the opening of the control switch. Also in the prior art devices, a second relay-controlled contact is used and is designed to close simultaneously with the holding contact to condition the bucking coil for energization through a circuit controlled by the opposite contact of the control switch.

The contact mechanisms of these old style devices require very accurate adjustment, if the control is to be made dependable. Too frequently, on energization of the bucking coil (and resultant motion of the armature to relay-open position) the circuit-conditioning contact opens before the holding contact, and the operating coil remains energized after the bucking coil has been de-energized, and it results that the armature moves back to relay-closed position. 0n the other hand, it happens that holding contact opens first (while the armature is moving .to relayopen position) and that the operating coil then acts to return the armature to relay-closed position. In either case, the result is continuous chattering, and failure to properly operate.

The present invention provides a relay control system in which the contact mechanism for maintaining energization of the operating coil, and for conditioning the bucking coil for energization, cannot be operated to permit one of the coils to be de-energized before the other, while the armature is moving to relay-open position.

Features of the invention include the details of wiring arrangement and connection, along with the broader ideas of means inherent in the disclosure.

Objects, features and advantages of the invention will be set forth in the description of the drawing forming part of this application, and said drawing consists of a single diagrammatic figure illustrating one embodiment.

In the drawing, the relay is indicated at 1 and comprises a first or operating coil 2, and a second neutralizing or bucking coil 3. 0n energization, the operating coil attracts an armature 4, moving it from its biased relay-open position to its relayclosed position. On relay closure, contact arms 5 and 6 are moved into engagement with respective contacts 7-8. Hereafter these switches will bereferred to as contacts 7 and 8. A source of power includes a primary 9 of a step-down transformer, the secondary of which, is indicated at 12. The power for the primary is provided by lines 10 and 11.

The relay control system is operated by any suitable switching mechanism, for example a thermostatic bimetallic element 13, which alternately controls hot and cold contacts, respectively indicated 14 and 15. This switch is only symbolic of other devices which may be used, and which may operate either automatically or manually.

The wiring connections will only be referred to numerically in detail under the heading Operation, but it will be noted-that, in this embodiment, one terminal of each of coils 2 and 3 is connected to the same side of the source 12; the opposite terminal of the bucking coil 3 is connected to one of the contacts 14 of the double contact switch; the opposite terminal of the operating coil 2 is connected through the contact 7 respectively with the opposite side of the source 12, and with the other contact 15 of the double contact switch; and the movable element 13 of the switch is circuit-connected at a point between the operating coil and the contact '7.

Of course, there is no intention to limit the invention entirely to the arrangement of the circuits above mentioned, because it is conceivable that the circuits might be difierently arranged to obtain a control which is characterized by the fact that the holding circuit for the relay and the energizing circuit for the bucking coil both pass through one and the same contact, which is controlled by the relay Operation 'On a call for heat, the element 13 moves in direction of the arrow to engage the contact 15, and the operating coil is energized through the following circuit: one side of source 12, 1.6, -17, contact 15, movable control element 13, 18, operating coil 2, 19, 20, to opposite side of source 12.

Armature is now attracted and contacts 7 and 8 are closed. Closure of contact 7 establishes a holding circuit for the operating coil as follows: one side of source 12, 16, 21, 5, '7, 22, operating coil 2, 19, 20 to 12. The operating coil will now remain energized after 13 leaves 15,011 a call for less heat, and while 13 moves toward contact 14.

Closure of contact 8 closes an external load circuit as follows: hot line 10, 23, 8, 6, 24, to load (not shown), from load through 25 to ground line 11. i

On closure of contact 14, the bucking coil 3 is energized through the following circuit: .one side of source 12, 16, 21, 5, '7, 22, 18, control element 13,

14, 26, bucking coil 3, 27, 20 to the opposite side of source 12. As is. well known, energization of the bucking coil results in neutralization of the magnetic eifects of the operating coil-2 so that the combined effect is zero, and the armature assumes relay-open position, opening. contacts 7 and 8, and conditioning the control to again close I the relay on a call for heat by the thermostat.

This invention, therefore, providesa single contact, which acts both to establish a holding circuit for the operating coil and to' condition the bucking coil circuit for energization, and since this holding circuit is closed on operating coil energization, it is always closed when the thermo-' stat closes contact 14 to. open the relay by energization of 'the bucking coil. The invention, therefore, not only. eliminates the use of an extra' contact, always required in otherdevices for. the

bucking coil circuit, but also eliminatsthe neces-= sity for careful and accurate adjustment of a plurality of contacts, and resultsin .acontrol" system which is dependableunder all conditionsof operation. r t I claim as my invention:

l. A relay system of the classdescribed com prising, in combination, an operating coll, a bucking coil, an armature operated to one position and maintained in "said position upon energization of the operatingcoil and allowed to move to a second position upon energization of the bucking coil while the operating coil ismain tained energized,la"contact arm'contr'olled by'thearmature, a cooperating contact, abimetallic element, a pair of I contacts engageable thereby, a source of power, a conductor connecting the source of power to one of the pair of contacts,'a conductor connecting the source of power to the contact'arm; conductors connecting the bimetallic element and the contact which cooperates with the contact arm to one side of the operating coil, a conductor connecting the other 01 the pair of contacts to one side of the bucking 'coil,'and conductors con necting the other sides of the operating and buck"- ing coils to the source of power. 2. Inc. device oi? the class described, a source of electric power, a relay having an operatingcoil and a bucking coil, a contact controlled by the relay, a double contact control switch including a movable contact-controlling member. and circuit connections in which one terminal of each coil is connected to the same side of the source.

in which the opposite terminal oi the bucking coil is connected to one of the contacts of-the control switch, in which the opposite terminal of the op-g erating coil is connected through'said relay-controlled contact respectively with the opposite side f th d with the 0 her contact of the o 8 Source an t l crating coll including therein the source and concontrol switch, andin which the movablemember of the switch is circuit-connected at a point between the operating coil and said relay-com' -when the same 'movesto its secondpo'sition, a

cell: a conductor connecting said'fourthterminal includingthe source and controlled only bythe and controlled only by the holding switch and the tion, said armature being movable to a second position upon energization of the operating coil only and being adapted to return to its first positionunder its bias upon subsequent energization of said bucking coil while said operating coil is still energized, a single circuit armature controlled switch moved to closed'position by the armature source .of power, a first control switch, a circuit for energizing the operating coil only and controlled by said first control switch, a holding circuit for maintaining-such energization of the operating coil controlled by the armature controlled switch only, a-second control switch and an energizing circuit for the bucking coil including the second control switch and the armature controlled switch.

. 4. A relaysystem of the class described, comprising in combination, an operating coil, a bucking coil, an armature normally biased to one position, said armature being movable to a second position upon energization of the operating coil only and being adapted to'return'to its first position under its bias upon subsequent energization of said bucking coil while said operating coil is 0 still energized,'a"single' circuit armature controlled switch moved to closed position by the armature when the same movesto its second position, asource of power, a first control switch, a circuit-for energizing the operating coil only and controlled by said firstycontrol switch, a holding circuit for maintaining such energization of the operating coil controlled by thearmature con,-

trolled switch only, a secondcontrolswitch, an energizing circuit for the bucking coil including the second control switch andthe armature controlled switch, and means responsive to variations 'inia physical condition for operating said first and second control switches.

5.- A relay system of the class described com-. prising, in combination, an operating-coil; a buck-; ing coil; an armature operated to one position and maintainedin said position upon energization of the operating coil and allowed to move to a second position upon energizationv of the bucking coil while the operating coil is maintained energized; a contact arm controlled by the armature; a cooperating contact; first and second control switches comprising first, second, third and fourth terminalsya source of-power; conductingmeans i interconnecting one side of the source of. power, said first terminal, and the contact arm; 'conducting means interconnecting said second and third terminals, the contact which. cooperates with the contact. arm. and one side of the operating to one side 01 the buck-ing coil; and conducting means interconnecting the other side of the opcrating coil. the. other side of the bucking coil, andthe other side of the source of power.

6. A relay. systemcomprising, an operating cell, a bucking coil, a first control switch, a second control switch. a holdingswitch and a source or electrical power. a clrcuitior'the operating coil.

first control switch. a holding circuit for the optrolled only by the holding switch, and a circuit for the bucking coll including therein the source second control switch.

e WILLIS H. GlLLE. 

